Heretofore, such as illustrated in U.S. Pat. No. 4,911,834 dated Mar. 27, 1990, vibratory screening devices or shakers have been provided for the separation of solids contained in a fluid. The fluid contained solids are moved along a vibratory mesh screen and the particles or solids of a size smaller than the openings in the mesh screen fall through the mesh screen into a collecting area. The larger particles or solids move along the mesh screen and are discharged from a rear end of the mesh screen into a suitable material handling device, such as a conveyor, for transport to a material collecting area.
While the vibratory screening device shown in U.S. Pat. No. 4,911,834 is used primarily in the separation of solids, such as entrained formation cuttings from drilling fluid being circulated in a well, the screening device may be utilized in separating fluid entrained solids from other fluids, such as, for example, separating various solids from waste water in a waste water treatment plant, or separating solids entrained in fluids for cleaning tanks or other receptacles. Thus, this type of fluid entrained solid material being separated from the fluid may vary dependent on the specific use being made of the vibratory screening device. The size of the mesh means would also vary dependent on the type of solid or particulate material desired to be removed or separated from the fluid which normally would be water.
In a waste water treatment plant, the waste water may contain fibrous particles, such as partially dissolved tissue paper, lint from fabric, and human hair which may tend to adhere to or mat over the mesh screen at certain locations to block or clog certain openings in the mesh screen thereby to impede the flow of fluid entrained solids along the mesh screen. It is apparent that other solid or particulate materials may tend to clog openings in the mesh screen, and particularly if the openings in the mesh screen are small.